Stitching apparatus



STITCHING APPARATUS Filed Oct. 3l, 1955 INVENToR ATTORNEYS Patented Dec. 1936 UNITED STATES PATENT FIC Max L. Engler, Akron, Ohio, assignor to The General Tire & Rubber Company, Akron, Ohio, a corporation of OhioV Application October 31, 1935, Serial No. 47,576

9 Claims. (Cl. 154-9) This invention relates to apparatus for builderably provided with an antifriction bearing 8 -ing pneumatic tires, and more particularly to within which the ends of a shaft 9 are journalled. ineans for stitching tire stock on the tire carcass. The shaft 9 is provided with right and left screw One of the objects of the present invention is to threads I ll, and one end I I of the shaft 9 projects provide new and improved means for stitching `through the arm I as shown in Fig. 4. This pro- 5 tire stock, and particularly the tread stock, to jecting end II of the shaft 9 is provided at its pneumatic tire casings. outer end with a fixed collar I2, and the bearing Another object of the present invention is to supporting portion of the arm I is provided with provide a stitching wheel for tire building maa fixed friction disk I3. Slidably mounted upon 10 chines of such construction that during the stitchthe end II of the shaft 9 between the collar I2 10 ing operation it has the tendency to crowd the and the disk I3 is a disklike member I4 having a material being stitched in the direction of rotafacing I5 of any suitable friction material. The tion, whereby to provide a more efficient stitching member I4 is provided with a sleeve portion I6 action. which surrounds the shaft end II and which is Another object is to provide a stitching wheel slotted at I'I to slidably receive a key I8 that is 15 for tire building apparatus in which the stitchcarried by the shaft end II, the key having suiing operation is accomplished by a plurality of l cient clearance with the slot I'I so that the sleeve radially movable stitching fingers. I6 will slide relative to the key `I8 and shaft end. With the above and other objects in view, the Surrounding the sleeve I6 is a compression spring present invention consists o-f certain features of I9, the ends of which engage with the disklike 20 construction and combinations of parts to be member I4 and the collar I2 to resiliently urge hereinafter described with reference to the acthe friction-faced member I4 against the fixed companying drawing, and then claimed. disk I3.

In the drawing, which illustrates asuitableem- Threadably mounted upon the right and left bodiment of the invention, threads is a pair of stitching wheels A, the one 25 Figure 1 is an end elevation of a tire building wheel being threaded on the right threads and drum showing the stitching apparatus associated the other wheel being threaded on the left threads therewith; as shown in Fig.2.

Fig. 2 is a side elevation of the apparatusshown Each of these' stitching =wheels comprises an in Fig. l; annular hub portion -2IJ ywhich carries a threaded 30 Fig. 3 is an enlarged view of the stitching wheel, sleeveZI `that is threaded on the. shaft as previa portion of the same being shown in section; cusly described,` the `hub portion- 2Il is valso pro- Fig. 4 is a section taken through the friction ided with a radially..circular disk portion 22. brake, taken approximately on the line 4 4 of The disk portion 22, as shownin Figs. 3 and 6, is

Fig. 2; formed with an outer axially extending circum- 35 Fig. 5 is a plan view of the stitching apparatus ferential flange 23 and an inner axially extending taken as looking in the direction of the arrows circumferential .flange24 which is concentric with 5-5 shown in Fig. 2; and the ilange 23 `and which is spaced therefrom.

Fig. 6 is an enlarged fragmentary view showing The flange 23 is provided with a. series of reguthe stitching wheel in the act of stitching the tire larly spaced radial openings, each of which carries 4.0 stock to the tire being constructed on the building an annular bushing 25. AThe inner flange 24y is drum, likewise provided with a series of regularly spaced Referring to the accompanying drawing, in openings -extending therethrough, each of which which like numerals refer to like parts throughis providedwth an annular bushing 26. Each 45, out the several views, the stitching apparatus of annular bushing 26 is in axial alignment with an 45 the present invention is shown in Figs. 1 and 2 as annular bushing 25.

being associated with a rotatable tire building Mounted within each'pair of bushings 25 and drum I which is rotatably supported by a stand- 26 for sliding movement is a pinlike member or ard 2. finger 21, the'outer end of which normally pro- The stitching apparatus includes abase portion jects radially beyond the flange 23 as shown in 50 3 having an upstanding arm 4 offset as shown in Fig. 3. `Each finger 2'I is 'provided with a collar Fig. l from the building drum I. Pivoted to the portion 28 which engages-with the inner face of arm 4 by means of a pivot pin 5 is a yokelike memthe flange 23 Vvtolimit the finger 2l against outber 6 having arms I which are located below the ward movement beyond its normal position, and

i tire building drum I. Eachofthearms I is prefsurrounding thefmemberr-2lis a` compression 55` spring 29 which has its ends engaged with the collar portion 28 and the circumferentially outer face of the flange 2t whereby to urge the member 21 to its normal position.

Associated with the stitching apparatus is a fluid pressure cylinder 30 having uid connections with a suitable valve 3l and a plunger (not shown) the plunger rod 32 of which is pivoted at 33 to alug 34 carried by the yoke E. The valve 3l is connected by means of a conduit 35 with a source of fluid pressure and is arranged to be operated by the foot pedal 3G shown in Figs. 1 and 5. k

Disposed below the stitching wheels, drums 31 are mounted on a rotatable shaft 38 that is journalled in a suitable bracket 39 secured to the base 3. The shaft 38 is driven by means of a belt 40 or any other suitable means from a Inotor driven gear box or speed reducing unit 4I.

During the operation of building up a tire carcass the drums 3'.' are continuously rotated in a counter-clockwise direction, as viewed in Fig. l, and normally the stitching wheels A rest upon the drums 31, which, during rotation, thread the wheels A inwardly toward each other, so that the hub portions 20 thereof abut each other, in which case the stitching wheels A'and shaft are rotated in a clockwise direction against the resistance of the disks I3 and I ll.

When it is desired to stitch the tire stock, such as tread stock, to the tire band which has been provided on the drumy I, the operator actuates the pedal 3S to open the valve 3l which allows fluid under pressure to act against the plunger pressure cylinder Sii and move the yoke 6 in an upward direction to bring the stitching wheels A into contact with the tread stock on the building drum. Suicient pressure is exerted by the plunger to depress the lingers 21 which are immediately below the stock on the tire building drum, as shown in Fig. 6, to allow the outer flange 23 to substantially engage with the tread stock B. Since the tire drum is rotating as viewed in Fig. l in a clockwise direction, the contact of the tread stock B with the outer ange 23 rotates the stitching wheels A in a counter-clockwise direction. Rotation of the wheels A causes them to thread outwardly away from each other on the shaft 9, the friction brake comprising the disks I3 and I4 holding the shaft against rotation to permit the outwardly threading movement of the stitching wheels A. The stitching wheels A are thus caused to travel from the central portion of the tread stock during their rotation outwardly towards and beyond the edges of the tread stock.

Inasmuch as the peripheral surface of the flange 23 rotates at the same peripheral speed as the stock being stitched, the outer ends of the fingers 21 which are not in contact with the tread stock B move at the higher peripheral speed. As they come in contact with the tread stock B they are gradually depressed radially inwardly, and their peripheral speed gradually decreases to the approximate speed of the flange 23, and because of this, the fingers 21 have a tendency to crowd the tread stock being stitched in a forward direction, or rather in the direction of travel of rotation of the tread stock B, and thus provide, through the crowding action, a more efficient stitching operation.

The threads I@ are so arranged that the stitching wheels will rotate several times during each revolution of the tire building drum I, so that the tread stock will be substantially continuously stitched at all points throughout its width.

After the stitching operation is completed one of the stitching wheels contacts with a member 42, which pivots to actuate the valve 3l through a shaft 43 and linkage 44, whereby the stitching wheels are lowered into position upon the drums 31. Since these drums are rotating in a direction opposite to the building drum I they cause the stitching Wheels A to thread axially inwardly along the shaft to their normal substantial abutting position. When the wheels A come into abutting engagement with each other, continued rotation of the drums 31 causes the shaft 9 to rotate, the pressure of the spring I9 being such that the friction disks I3 and I4 will allow the shaft 9 to rotate.

While I have shown a fluid pressure cylinder for moving the stitching wheels into engagement with the material on the tire building drum, it is to be understood that other means may be provided for producing this engagement and also that the shaft for the stitching wheels may be supported in any suitable manner.

Although a single embodiment of the invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined in the following claims.

What I claim is:

1. A stitching wheel comprising a rotatable member, a plurality of radial stock engaging elements mounted on said member for sliding movement radially of said member and having their radially outermost ends normally projecting radially beyond the periphery of said member, and resilient means urging said elements toward their normal projecting position.

2. A stitching wheel comprising a rotatable member, a plurality of radial stock engageable elements mounted on said member for sliding movement radially of said member, said elements having their outermost ends projecting radially beyond the periphery of said member and having stop means normally engageable with said member to predetermine the normal projecting position thereof, and resilient means for resiliently opposing radially inward movement of said elements.

3. A stitching wheel comprising a rotatable disk-like member having a plurality of radial openings therein, stock engaging elements slidably mounted in said openings and having their ends normally projecting beyond the periphery of said member, stop means for limiting said elements to their normal projecting position, and resilient means for resiliently opposing radially inward sliding movement of said elements.

4. A stitching wheel comprising a rotatable member, an outer series of circumferentially arranged radial openings, an inner series of circumferentially arranged radial openings spaced therefrom, each opening of one series: being axially aligned With an opening of the outer series, a plurality of pinlike elements, each element being slidably mounted in a pair of the aligned openings and having its outer end normally projecting beyond the periphery of said member, each element having a shoulder thereon normally engaging the innermost edge portions of the outermost opening, and a coiled spring having one end engaged with said shoulder and its opposite end engaged with the outer most edge portion of the innermost opening.

5. A stitching wheel comprising a disk-like member having spaced axially-extending annular flanges, a series of radial openings in each of said anges, each opening of one flange being aligned with an opening of the other flange, a pin-like element slidably mounted in each pair of aligned openings and having its outer end normally projecting beyond the periphery of said member, each element having a transverse portion normally engaging the radially inner surface of the radially outer flange, and a coiled spring surrounding the pin-like element and having its ends abutting said transverse portion and the radially outer surface of the radially inner iiange.

6. The combination with a rotatable tire building drum of a rotatable stitching wheel rotatable through contact with the tire material on said drum to be stitched, comprising a rotatable member, a plurality of radial stock engageable elements, means for slidably supporting said elements on said member with the ends thereof normally projecting beyond the periphery of said member, and resilient means for resiliently opposing radially inward movement of said elements.

7. The combination with a rotatable tire building drum of a rotatable stitching wheel rotatable through contact with the tire material on said drum to be stitched, comprising a rotatable member, a plurality of radial stock engageable elements, means for slidably supporting said elements on said member with the ends thereof normally projecting beyond the periphery of said member, resilient means for resiliently opposing radially inward movement of said elements, a supporting structure for said stitching wheel and means for holding said wheel in engagement with the material on said drum with a pressure sufficient to move said stock engageable elements radially inwardly upon engagement with the tire material on said drum.

8. The combination with a rotatable tire building drum, of a stitching apparatus comprising a right and left threaded screw shaft, a pair of stitching wheels, one being threaded on the right threaded portionof said shaft and the other being threaded on the left threaded portion of said shaft, said stitching wheels normally being substantially engaged with each other at a region intermediate the ends of said shaft, a support for rotatably supportingv the ends of said shaft, means for moving said support towards said drum whereby to move said wheels into pressure engagement with the tire material on said drum whereby rotation of said drum causes said wheels to thread outwardly along said shaft and stitch said tire material, frictional slip means associated with said shaft and support to hold said shaft against rotation during the stitching operation, and means rotatable in a direction opposite to said drum, said stitching wheels being engageable with said last mentioned means whereby rotation of said last mentioned means threads said wheel axially inwardly along said shaft to their normal substantially abutting portions.

9. The combination with a rotatable tire building drum, of a stitching apparatus comprising a right and left threaded screw shaft, a pair of stitching wheels, one being threaded on the right threaded portion of said shaft and the other being threaded on the left threaded portion of said shaft, said stitching wheels normally being substantially engaged with each other at a region intermediate the ends of said shaft, a support for rotatably supporting the ends of said shaft, means for moving said support towards said drum whereby to move said wheels into pressure engagement with the tire material on said drum whereby rotation of said drum causes said wheels to thread outwardly along said shaft and stitch said tire material, frictional slip means associated wtih said shaft and support to hold said shaft against rotation during the stitching opf 

